OCCURRENCE OF CHALKBROOD CAUSED BY ASCOSPHAERA AGGREGATA SKOU IN A NATIVE LEAFCUTTING BEE, MEGACHILE PUGNATA SAY (HYMENOPTERA: MEGACHILIDAE), IN SASKATCHEWAN

1992 ◽  
Vol 124 (3) ◽  
pp. 557-558 ◽  
Author(s):  
D.W. Goerzen ◽  
L. Dumouchel ◽  
J. Bissett
Keyword(s):  
United States ◽  
Seed Production ◽  
Western Canada ◽  
Nest Material ◽  
Megachile Rotundata ◽  
Alfalfa Seed ◽  
Low Levels

The alfalfa leafcutting bee, Megachile rotundata (Fab.), is a domesticated pollinator important for alfalfa seed production in western Canada. Populations of M. rotundata are highly susceptible to chalkbrood, a disease caused by the fungus Ascosphaera aggregata Skou. The disease has caused high mortalities in M. rotundata populations in the northwestern United States since 1972. It was found in Manitoba in 1982, Alberta in 1983, and Saskatchewan in 1984 (Richards 1985). In subsequent surveys, A. aggregata has been detected only sporadically and at low levels of infection in Saskatchewan M. rotundata populations (Goerzen 1991). A previously reported observation of A. aggregata in the native leafcutting bee M. relativa Cresson (Goerzen et al. 1990) indicated that the disease is present in native leafcutting bee species which commonly immigrate into alfalfa leafcutting bee nest material.

EFFECT OF TWO INSECT VIRUSES AND TWO ENTOMOPATHOGENIC FUNGI ON LARVAL AND PUPAL DEVELOPMENT IN THE ALFALFA LEAFCUTTING BEE, MEGACHILE ROTUNDATA (FAB.) (HYMENOPTERA: MEGACHILIDAE)

1990 ◽  
Vol 122 (5) ◽  
pp. 1039-1040 ◽  
Author(s):  
D.W. Goerzen ◽  
M.A. Erlandson ◽  
K.C. Moore
Keyword(s):  
Apis Mellifera ◽  
Insect Pest ◽  
Microbial Control ◽  
Western Canada ◽  
Pest Species ◽  
Megachile Rotundata ◽  
Pupal Development ◽  
Canadian Prairies ◽  
Alfalfa Seed ◽  
Beneficial Insect

The alfalfa leafcutting bee, Megachile rotundata (Fab.), is an important pollinator of alfalfa in western Canada and is widely utilized for alfalfa seed production (Richards 1984). As a beneficial insect, the alfalfa leafcutting bee must be considered, along with the honey bee, Apis mellifera L., as a non-target organism of importance in evaluations of potential microbial control agents for use against major insect pest species on the Canadian prairies.

scholarly journals Occurrence of Transgenic Feral Alfalfa (Medicago sativa subsp. sativa L.) in Alfalfa Seed Production Areas in the United States

PLoS ONE ◽  
2015 ◽  
Vol 10 (12) ◽  
pp. e0143296 ◽  
Author(s):  
Stephanie L. Greene ◽  
Sandya R. Kesoju ◽  
Ruth C. Martin ◽  
Matthew Kramer
Keyword(s):  
United States ◽  
Medicago Sativa ◽  
Seed Production ◽  
The United States ◽  
Alfalfa Seed ◽  
Production Areas ◽  
Feral Alfalfa

DETECTION OF A CHALKBROOD FUNGUS, ASCOSPHAERA AGGREGATA, IN LARVAE OF THE ALFALFA LEAFCUTTER BEE (HYMENOPTERA: MEGACHILIDAE) FROM WESTERN CANADA

1985 ◽  
Vol 117 (9) ◽  
pp. 1143-1145 ◽  
Author(s):  
K.W. Richards
Keyword(s):  
United States ◽  
The United States ◽  
Fungal Disease ◽  
Western Canada ◽  
Megachile Rotundata ◽  
Severe Problem ◽  
Leafcutter Bee

The alfalfa leafcutter bee, Megachile rotundata (F.), is the primary pollinator of commercially grown seed alfalfa in Canada. Chalkbrood is a fungal disease, caused by a complex of Ascosphaerales species (Skou and King 1984) that infect the larvae of many species of bees. One species, Ascosphaera aggregata Skou (Skou 1975), is a severe problem in leafcutter bees in the United States and in some cases has caused losses of more than 65% (Stephen et al. 1981). Mode of dispersal, infestation of bee larvae, sporulation, and associated symptomatology of this pathogen have been described (Vandenberg et al. 1980; Vandenberg and Stephen 1982; McManus and Youssef 1984).

OCCURRENCE OF CHALKBROOD CAUSED BY ASCOSPHAERA AGGREGATA SKOU IN A NATIVE LEAFCUTTING BEE, MEGACHILE RELATIVA CRESSON (HYMENOPTERA: MEGACHILIDAE), IN SASKATCHEWAN

1990 ◽  
Vol 122 (6) ◽  
pp. 1269-1270 ◽  
Author(s):  
D.W. Goerzen ◽  
M.A. Erlandson ◽  
J. Bissett
Keyword(s):  
United States ◽  
Megachile Rotundata ◽  
Southern Alberta ◽  
Low Levels

The alfalfa leafcutting bee, Megachile rotundata (Fab.), is an important domesticated pollinator of alfalfa grown for seed in Canada. Chalkbrood, a disease caused by the fungus Ascosphaera aggregata Skou, has caused high mortalities in M. rotundata populations in the northwestern United States since 1972. Chalkbrood was found in Manitoba in 1982, Alberta in 1983, and Saskatchewan in 1984 (Richards 1985). Although subsequent surveys have indicated the presence of A. aggregata at high levels in some southern Alberta M. rotundata populations, the disease has been detected only sporadically and at low levels in Saskatchewan populations (Goerzen 1990).

scholarly journals Household COVID-19 risk and in-person schooling

Science ◽  
2021 ◽  
pp. eabh2939
Author(s):  
Justin Lessler ◽  
M. Kate Grabowski ◽  
Kyra H. Grantz ◽  
Elena Badillo-Goicoechea ◽  
C. Jessica E. Metcalf ◽  
...  
Keyword(s):  
United States ◽  
Online Survey ◽  
Positive Association ◽  
The United States ◽  
Mitigation Measures ◽  
Office Work ◽  
School Based ◽  
Increased Risk ◽  
Extra Curricular Activities ◽  
Low Levels

In-person schooling has proved contentious and difficult to study throughout the SARS-CoV-2 pandemic. Data from a massive online survey in the United States indicates an increased risk of COVID-19-related outcomes among respondents living with a child attending school in-person. School-based mitigation measures are associated with significant reductions in risk, particularly daily symptoms screens, teacher masking, and closure of extra-curricular activities. A positive association between in-person schooling and COVID-19 outcomes persists at low levels of mitigation, but when seven or more mitigation measures are reported, a significant relationship is no longer observed. Among teachers, working outside the home was associated with an increase in COVID-19-related outcomes, but this association is similar to other occupations (e.g., healthcare, office work). While in-person schooling is associated with household COVID-19 risk, this risk can likely be controlled with properly implemented school-based mitigation measures.

scholarly journals Seed production of barnyardgrass (Echinochloa crus-galli) in response to time of emergence in cotton and rice

2011 ◽  
Vol 150 (6) ◽  
pp. 717-724 ◽  
Author(s):  
M. V. BAGAVATHIANNAN ◽  
J. K. NORSWORTHY ◽  
K. L. SMITH ◽  
P. NEVE
Keyword(s):  
United States ◽  
Seed Production ◽  
Herbicide Resistance ◽  
Crop Production ◽  
Integrated Management ◽  
Resistance Management ◽  
Simulation Models ◽  
Effective Resistance ◽  
Southern United States

SUMMARYThe spread of herbicide resistance in barnyardgrass (Echinochloa crus-galli(L.) Beauv.) poses a serious threat to crop production in the southern United States. A thorough knowledge of the biology of barnyardgrass is fundamental for designing effective resistance-management programmes. In the present study, seed production of barnyardgrass in response to time of emergence was investigated in cotton and rice, respectively, in Fayetteville and Rohwer, Arkansas, over a 2-year period (2008–09). Barnyardgrass seed production was greater when seedlings emerged with the crop, but some seed production was observed even if seedlings emerged several weeks after crop emergence. Moreover, barnyardgrass seed production was highly variable across environments. When emerging with the crop (0 weeks after crop emergence (WAE)), barnyardgrass producedc. 35 500 and 16 500 seeds/plant in cotton, andc. 39 000 and 2900 seeds/plant in rice, in 2008 and 2009, respectively. Seed production was observed when seedlings emerged up to 5 WAE (2008) or 7 WAE (2009) in cotton and up to 5 WAE (2008, 2009) in rice; corresponding seed production wasc. 2500 and 1500 seeds/plant in cotton, andc. 14 700 and 110 seeds/plant in rice, in 2008 and 2009, respectively. The results suggest that cultural approaches that delay the emergence of barnyardgrass or approaches that make the associated crop more competitive will be useful in integrated management programmes. In the context of herbicide resistance management, it may be valuable to prevent seed return to the seedbank, irrespective of cohorts. The findings are vital for parameterizing herbicide resistance simulation models for barnyardgrass.

Spittle Bugs in Relation to Alfalfa Seed Production in Wisconsin

1947 ◽  
Vol 40 (3) ◽  
pp. 446-448 ◽  
Author(s):  
J. M. Scholl ◽  
J. T. Medler
Keyword(s):  
Seed Production ◽  
Alfalfa Seed

The United States Congress and Africanist Scholars

1991 ◽  
Vol 19 (2) ◽  
pp. 4-13
Author(s):  
David S. Wiley
Keyword(s):  
United States ◽  
Foreign Policy ◽  
The United States ◽  
African Studies ◽  
United States Congress ◽  
The Poor ◽  
Low Levels ◽  
The U.S

Linking scholars to the Congress is difficult primarily because of the weakness of Congressional interest in Africa, but also due to the low levels of interest among academics in both Congress and its Africa foreign policy and the poor resources of African studies in the U.S. to build a foundation of knowledge useful to the Congress.

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